Great summary! It may be good to add the warning that after resuming from suspend to s2idle, power consumption is way higher because only power states down to C3 are used (see Issues with power usage - #5 by Brad_J). This would seem a straight-up bug (not sure it is the kernel or bios). After a deep suspend, things are back to normal. But resuming from deep suspend takes rather long (also a bug?).
Maybe useful for others, my measurements with powertop (i7, 32GB, 3.07 bios; Debian/KDE,X11,pipewire, konsole only, radios off (flight mode), removed HDMI extension card
- screen at 5%: 2.0 W, CPU 95% in C10
- screen at 50%: 3.1 W
- screen at 100%: 4.3 W
- screen at 5%, insert HMDI: 2.9 W
- after autosuspend HDMI: 2.4 W
- screen at 5%, HDMI removed, radios on: 2.2 W (connected or not makes little difference)
- after s2idle suspend, radios off: 4.4 W; EDIT: this is solved with
nvme.noacpi=1- see Linux battery life tuning - #156 by technical27 - after deep suspend: 2.0 W
Overall, idle power of ~2W (presumably, window manager turns screen off; ~2.4W at 100%) seems very reasonable! But concrete things/bug fixes that would make it generally happen are:
- Ensure regular state after s2idle resume (and, it sounds like, make s2idle better!); EDIT: regular state can be ensured - see Linux battery life tuning - #156 by technical27
- Ensure HDMI dongle uses less power (beyond what is gained from suspending it)
- Somehow make resume from deep suspend faster?
p.s. For reference, my old X1 Yoga 2nd gen also has an idle power consumption of ~2W.